Flexible display is a competitive display technology in the future. Common OLED (Organic Light Emitting Diode) flexible display apparatus include a display panel and a touch panel on an upper surface thereof. The display panel includes a light emitting area and a non-light emitting area, and the touch panel includes a plurality of horizontal and vertical electrodes having a grid shape. In order to make the flexible display apparatus thinner and lighter, as shown in FIG. 1, the touch panel is directly fabricated above the encapsulation layer, and the touch electrode is only about ten microns away from the cathode, resulting in a large coupling capacitance between the emitter and receiver electrodes and the cathode. Therefore, most of the electric field lines are sucked by cathode, only a very small part thereof can reach to electric field lines are absorbed by the cathode, only a very small part thereof can reach to the receiver electrode. As shown in FIG. 2, when the finger touches, the amount of variation of the electric field of the receiver electrode is very small. When the cathode voltage changes with the display mode of the mobile phone (for example, when the display screen is dark or light) (e.g., −1V˜−5V), the electric quantity of the coupling capacitance between the emitter and receiver electrodes and the cathode may be changed, resulting in the change of the amount of variation of the electric field of the receiver electrode, thereby affecting the touch performance.